SK Inc., the holding company of SK Group, announced Friday that it has signed a 2.3 trillion-won ($1.6 billion) agreement to sell its controlling stake in SK Siltron, a semiconductor wafer manufacturer, to Doosan Group.

The decision was approved at a board meeting held earlier in the day. According to a regulatory filing, SK will divest its 70.6 percent stake in the affiliate to Doosan, a major South Korean engineering and energy conglomerate.

The transaction follows SK's selection of Doosan as the preferred bidder in December, approximately seven months ago. That selection came after an evaluation process that considered corporate growth potential, job stability, and other acquisition terms.

SK Siltron, headquartered in Gumi, North Gyeongsang Province, was established in 1983. It is South Korea's only dedicated producer of semiconductor wafers — thin slices of crystalline silicon that serve as the foundational substrate for virtually all integrated circuit manufacturing. The company holds the third-largest global market share in 12-inch wafers, the standard size used in advanced semiconductor fabrication. The global silicon wafer market is dominated by a handful of suppliers, with Japan's Shin-Etsu Handotai and SUMCO holding the top two positions, making domestic wafer production a matter of strategic priority for South Korea, whose broader semiconductor industry is anchored by memory giants Samsung Electronics and SK Hynix.

For Doosan, the acquisition represents a significant step in expanding its semiconductor materials and equipment portfolio, which the conglomerate has identified as a key future growth area. The group has previously acquired Doosan Tesna Inc., a semiconductor testing company, and Engion, a chip packaging firm, as part of the same strategy. Doosan has set a target of growing SK Siltron's revenue to approximately 3 trillion won by 2031.

SK Group's decision to divest SK Siltron is part of a broader restructuring initiative launched last year. South Korea's second-largest conglomerate has been streamlining its business portfolio to improve financial soundness and concentrate resources on core growth areas, including its flagship chipmaking arm SK Hynix, which has been investing heavily in advanced memory and high-bandwidth memory used in artificial intelligence infrastructure.

The deal underscores ongoing consolidation in the global semiconductor supply chain, where major industrial groups are increasingly seeking vertical integration across materials, manufacturing, testing, and packaging. The transaction is expected to close pending regulatory approvals.